Bagmaking machine

ABSTRACT

A deflector is disposed between the bottom laying and delivery stations and is controlled by bottom checking devices to reject defective bags from the path of travel. The sensing elements for the path of travel of the inner halves of the bag end portions consist of photodetectors for receiving reflected light, which cooperate with stationary reflecting elements, which are intended to enter between the upper ply of the bag and the bag bottom.

United States Patent Inventor Appl. No

Filed Patented Assignee Priority Karl Wiendieck Sutthausen, Osnabruck, Germany 773,079

Nov. 4, 1968 June 1, 1971 Windmolle & Hostche Westphalia, Germany Nov. 6, 1967 Germany BAGMAKING MACHINE 5 Claims, 3 Drawing Figs.

U.S.Cl

lnt.Cl

Field of Search B65b 57/04, B65b 65/08 93/8, 8 (WA), 35 (RB), 93 (C), 93 (.3); 53/53, 54

[56] References Cited UNITED STATES PATENTS Re25,018 8/1961 Howdle 93/93(.3) 2,922,519 1/1960 Radley 53/53X 3,243,033 3/1966 Merchant.. 93/93(.3) 3,282,173 11/1966 Davis 93/8 3,359,702 12/1967 Beert 53/53 3,380,587 4/1968 Stork 93/35(RB) 3,415,369 12/1968 Hennig 53/53X 3,420,149 1/1969 Middleditch 93/93(C) 3,469,506 9/ 1969 Stork 93/35(RB) Primary Examiner-Wayne A. Morse, Jr. Attorney--Fleit, Gipple and Jacobson ABSTRACT: A deflector is disposed between the bottom laying and delivery stations and is controlled by bottom checking devices to reject defective bags from the path of travel. The sensing elements for the path of travel of the inner halves of the bag end portions consist of photodetectors for receiving reflected light, which cooperate with stationary reflecting elements, which are intended to enter between the upper ply of the bag and the bag bottom.

2 Sheets-Sheet l FIGJ I I s 15:74 x ,1 g) l0 i I I l v INVENTOR & Karl WIENDIECK V A I his ATTORNEY Patented FIG. 21 i vJune 1,, 1971' 2 Sheets-Sheet 2 his ATTGRNEYS BAGMAKING MACHINE The invention relates to an improvement of the invention described in the specification and illustrated in the drawing of the US. Pat. No. 3,380,587. Said specification and drawing will be referred to hereinafter as the first prior disclosure.

The first prior disclosure relates to a bagmaking machine which comprises a deflector, which is disposed between the bottom laying and delivery stations and is controlled by bottom checking devices to reject defective bags from the path of travel. According to said first prior disclosure, the bottom checking devices comprise sensing elements for each of the inner and outer bottom edges of each bag bottom and additional sensing elements for the bottom patches. The error signal from each sensing element causes a deflection of the deflector. According to a second prior disclosure contained in the U5. Pat. application Ser. No. 684,327 filed Nov. 20, 1967, additional sensing elements are provided for checking crossed-bottoms as to the presence and agreement of the actual and desired positions of the oblique edges of the infolded comer portions; and one of these additional sensing elements is provided in the path of travel of the outerand inner halves of each bottom.

The contours of the outer halves of the flattened crossedbottoms may be checked in a simple manner with the aid of photoelectric sensing elements. On the other hand, the inner halves of the bottoms have been reversely folded onto the bag workpieces so that they do not permit photoelectric checking. According to still earlier proposals of the assignees, these inner halves of the bottoms can be checked by mechanical sensing elements, but these are not reliable at relatively high machine speeds and do not have an adequate sensitivity in sensing relatively thin workpieces. It has also been previously proposed to replace the mechanical sensing elements in the range where the inner halves of the bottoms are to be sensed by a source of radioactive radiation, preferably beta radiation, and to provide beyond the plane of travel of the workpieces a scintillation counter so that the number of plies of the bag workpieces in the sensed area is ascertained and compared to the desired number of plies. Although sensing by nuclear radiation is satisfactory and the use of beta radiation does not require extensive safety precautions, it will generally be uneconomical because it involves extremely high costs.

It is thus an object of the invention to provide for the checking of the contours of the inner halves of the bag bottoms in bagmaking machines of the kind first described by an apparatus which is satisfactory in operation and can be manu factured at economically reasonable costs. This object is accomplished according to the invention in that the sensing elements for the path of travel of the inner halves of the bag bottoms consist of photodetectors for receiving reflected light, which cooperate with stationary reflecting elements, which are intended to enter between the upper ply of the bag and the bag bottom. The reflecting elements enable a satisfactory photoelectric sensing of the inner halves of the bottoms because they enable an exact checking, just as in connection with the outer halves of the bottoms, as to whether the actual position of the contour of the bag is in agreement with the desired position at a given time during the cycle of operation of the machine. This applies to the correct position of the inner edges of the bottoms and of the oblique edges of the infolded corner portions.

An improvement of the bagmaking machine according to the invention accomplishes the object by designing the reflecting element so that it will always reliably enter between the inner half of the bottom and the body of the bag workpieces which move continuously through the bagmaking machine wherein the bag workpieces do not strike against the reflecting element whereby they could be damaged or blocked. This object is accomplished by the invention with a minimum expenditure of cost and material so that bagmaking machines which are already in operation can be subsequently provided in a simple manner with the checking device proposed by the invention.

This development resides mainly in that the reflecting element has a platelike main part, which extends substantially parallel to the plane of conveyance and is provided with a reflecting surface portion. The distance of said main part from the plane in which the workpieces are conveyed exceeds the maximum thickness of the workpieces to be checked, and said main part is provided at its forward edge with a guiding element, which is articulately secured to said forward edge by a flexible element or a hinge in such a manner that the guiding element is biased toward the plane of conveyance. The guiding element may be secured to the main part by one or more leaf springs and the leaf springs are under slight initial stress toward the plane of conveyance. Alternatively, the guiding element may bear simply under the action of gravity on the workpieces. The distance between the platelike main part and the plane of conveyance and the articulate connection of the guiding element urged against the bag workpieces, ensure that the guiding element always enters between the bag wall and the inner half of the bottom and damage to or a blocking of the bag by the reflecting element will be reliably avoided.

The guiding element may be laterally bent away from the plane of conveyance at that end of its forward edge which is not intended to enter between the bag wall and the bag bottom so that the bag will be still more reliably guided under the guiding element and the reflecting element.

According to another proposal ofthe invention, the forward edge of the guiding element is at such an oblique angle to the direction of conveyance that the bottom corner of the inner half of the bottom of each bag reaches the guiding element first. If the bottom edge of the bag reaches the oblique edge of the guiding element first, the inner half of the-of the bottom will be raised most easily because a longer lever arm is available than if the first workpiece portion reaching the bag would be close to the center fold line of the bottom. The arrangement of the forward edge proposed according to the invention results also in a point contact with the inclined leading edge of the bottom so that the raising is also facilitated.

The invention will be explained more fully in the following description with reference to an embodiment shown by way of example on the accompanying drawing, in which FIG. 1 is a top plan view showing a reflecting element according to the invention,

FIG. 2 is a side elevation showing the reflecting element according to the invention, and

FIG. 3 is a sectional view taken on line III-III in FIG; 1.

The reflecting element according to the invention com prises a main portion 301, which is secured by angled lugs 302 to a machine frame, now shown. The angled lugs 302 are formed with elongated holes 303, through which the fixing screws, not shown, are passed. The elongated holes 303 enable such an adjustment of the reflecting element with reference to the plane of conveyance, indicated at 304-in FIG. 3, that there is-always a distance-which exceeds the maximum thickness of the bag workpieces between the main part 301 of the reflecting element and the plane of conveyance 304.

By means of screws 305, the actual reflecting elements 306 are clamped -to the main part 301 and disposed under windows 307 formed in a'plate 308. By means of screws 310 and 312 two leaf springs 311 are secured along the oblique forward edge 309 of the main part 301 and are connected by screws 312 to a guiding element 313. The heads of the screws 310 and 312 are received by two pairs of plates 3110, which rest on the leaf springs 311 and have edges 3llb that are bevelled in a direction opposite to the direction of travel (FIG. 3). The leaf springs 311 are prestressed so that the guiding element 313 is slightly urged toward the plane of conveyance 304, as is shown in FIG. 3. The forward edge 314 of the guiding element 313 is wedge-shaped and extends at an oblique angle to the direction of conveyance 315 of the bag workpiece 316. Those ends of the guiding element 313 and of the main part 301 of the reflecting element which are not intended to enter between the body of the bag workpieces 316 and the inner halves 317 of their bottoms 318 are bent upwardly at 319 and 320.

In operation, the bent-up ends 319 and 320 ensure that the bag workpiece 316 reliably enters under the reflecting element. As the guiding element 313 snugly engages the bag workpiece 316 under spring pressure its forward edge 314 is oblique relative to the direction of conveyance 315, and the end comer 321 of the inner half 317 of the bag bottoms will reliably move on top of the guiding element 313 and then on the main part 301 of the reflecting element, where the workpiece can be sensed by the photodetector for receiving reflected light when the reflecting surface 306 has been reached by the workpiece lclaim:

1. A machine for making bags having at least one folded bottom with one-half thereof resting on the bag, said machine comprising a bottom laying station, a delivery station, means defining a path of conveyance between said stations, 21 movable deflector interposed in said path of conveyance for diverting defective bags from said delivery station to a waste delivery station, bottom checking sensing means for checking bags moving along said path of conveyance and for actuating said movable deflector responsive to sensing a defective bag to cause the defective bag to be diverted to said waste delivery station, said sensing means comprising photodetectors for receiving reflected light and stationary reflecting means adapted to enter between the bag and said bottom half resting on the bag when the bag is moved along said path of conveyance, said stationary reflecting means comprising a platelike main part extending substantially parallel to said path of conveyance and provided with a reflecting portion at its surface, said platelike main part being positioned a distance from said path of conveyance exceeding the maximum thickness of the bag, and a guiding element secured to said main part at its front edge and biased toward said path of conveyance.

2. A machine according to claim 1 wherein said guiding element is secured to said main part by at least one leaf spring, each said leaf spring being under slight initial stress toward said path of conveyance.

3. A machine according to claim 1, wherein said guiding element is articulately secured to said front edge and bears under the action of gravity on the bags 4. A machine according to claim 1, wherein said guiding element is laterally bent away from said path of conveyance at an end of said front edge which is not intended to enter between the bag and said bottom half.

5. A machine according to claim 1, wherein said front edge of said guiding element extends at an oblique angle to said path of conveyance allowing the leading corner of said bottom half to reach said guiding element first. 

1. A machine for making bags having at least one folded bottom with one-half thereof resting on the bag, said machine comprising a bottom laying station, a delivery station, means defining a path of conveyance between said stations, a movable deflector interposed in said path of conveyance for diverting defective bags from said delivery station to a waste delivery station, bottom checking sensing means for checking bags moving along said path of conveyance and for actuating said movable deflector responsive to sensing a defective bag to cause the defective bag to be diverted to said waste delivery station, said sensing means comprising photodetectors for receiving reflected light and stationary reflecting means adapted to enter between the bag and said bottom half resting on the bag when the bag is moved along said path of conveyance, said stationary reflecting means comprising a platelike main part extending substantially parallel to said path of conveyance and provided with a reflecting portion at its surface, said platelike main part being positioned a distance from said path of conveyance exceeding the maximum thickness of the bag, and a guiding element secured to said main part at its front edge and biased toward said path of conveyance.
 2. A machine according to claim 1 wherein said guiding element is secured to said main part by at least one leaf spring, each said leaf spring being under slight initial stress toward said path of conveyance.
 3. A machine according to claim 1, wherein said guiding element is articulately secured to said front edge and bears uNder the action of gravity on the bags.
 4. A machine according to claim 1, wherein said guiding element is laterally bent away from said path of conveyance at an end of said front edge which is not intended to enter between the bag and said bottom half.
 5. A machine according to claim 1, wherein said front edge of said guiding element extends at an oblique angle to said path of conveyance allowing the leading corner of said bottom half to reach said guiding element first. 